Princess Luna, from the popular animated series My Little Pony: Friendship is Magic, is not married. While she has been romantically linked to other characters in the series, such as Discord, her romantic life is largely unexplored in the show.
It's important to remember that Princess Luna is a fictional character and her marital status is determined by the creators of the show. While fans may speculate or create fan fiction exploring her potential relationships, the official canon of the show does not depict her as married.